When a general camera is used to obtain information of an object in a space, a lens thereof is generally focused to a particular object distance to pickup a clear image of the object on such object distance. Regarding objects of other object distances, if the objects are within a coverage of a depth of field, clear images of the objects can still be obtained. However, if the objects are out of the coverage of the depth of field, unclear object images are obtained.
Moreover, regarding distribution and configuration information of each of the objects in the space, the general camera only obtains two-dimensional (2D) information of the object corresponding to a certain viewing angle, which is lack of distribution information of each of the objects in a depth direction. Therefore, based on the 2D image obtained by the general camera, distribution of each of the objects in the three-dimensional (3D) space cannot be sufficiently learned.
Therefore, a light field camera is developed, which is capable of sufficiently obtain distribution and configuration information of each of the objects in the 3D space. However, in the present light field camera, regardless of whether a lens array method or a lens set array method is used, a system pixel usage rate thereof is relatively low due to that each sub image has a trend of crosstalk minimization, which influences a pixel number of a final output image of the light field camera. For example, the pixel number of the output image of the light field camera is about 10% to 65% of the pixel number of the used image sensor.